Really, a good summoner is always considering what their pet is doing and puts their pet to good use.
In most fights, this simply means:

-Set pet to attack boss
-Use rouse/spur/contagion whenever they are up
-done

...and you don't have to care about it anymore. For other fights with adds, it's simply a matter of occasionally pressing your favorite keybind to tell it to attack new targets. Like I said, it's basically a DoT you move between targets - there is no interesting gameplay here, let alone "pet gameplay." You do have to keep it alive as well, but only on some fights you have to care about this, and sometimes it's just a matter of one move command and it's good for the entire fight.

Anyways, we got some news from the niconico interview that they're looking to rebalance Ifrit/Titan before the new egis come out, so that's good news.